Known medical procedures that employ catheterization, typically involve use of a plurality of catheters in sequence. Specifically, several catheters may be inserted into a same body conduit and removed from it, sequentially, to perform a sequence of steps of a medical procedure. To take an example, in cryosurgical ablation of prostate tissue, a procedure may typically involve a step of insertion of a guiding catheter into the urethra for identifying the urethral course during ultrasound-guided needle insertion. A next step may involve removal of the guiding catheter and insertion into the urethra of a treatment catheter. Such a treatment catheter may be for example a warming catheter used to protect the urethra during cryoablation, or, as another example, a urethral straightener connected to a probe guidance mechanism as taught by Zvuloni et al. in U.S. Pat. No. 7,670,333 and in Patent Application US20090118724. A next step may involve removal of the treatment catheter and insertion of a post-procedure drainage catheter. Finally, the drainage catheter must also be removed. Various other well-known treatment procedures similarly require two or three or more sequential catheter insertions and removals.